Food colours explained: the six with a warning label, and why

Food colours are the only additive class carrying a mandatory warning label in Europe. People cite the study behind that warning to argue both that colours are harmful and that they are harmless, and it does not cleanly support either.

What they are and why they exist

Colour changes how food tastes. In blind tests a grey strawberry yoghurt tastes weaker than the same yoghurt tinted pink, including to people who say colour does not matter to them.

Two groups sit on the label. Natural colours come from plants and insects: turmeric, beetroot, paprika extract, carmine from cochineal insects, caramel from heated sugar. Synthetic colours are made in a factory, mostly from petroleum feedstocks, and they are brighter, cheaper and far more stable in light and heat.

The full list

Every food colour in our database, with its E number.

Food	Notes
Ponceau 4rE124	Ponceau 4r (E124) is a colour food additive.
Quinoline yellowE104	Quinoline yellow (E104) is a colour food additive.
CarmoisineE122	Carmoisine (E122) is a colour food additive.
ErythrosineE127	Erythrosine (E127) is a colour food additive.
Brilliant blueE133	Brilliant blue (E133) is a colour food additive.
Titanium dioxideE171	Titanium dioxide (E171) is a colour food additive.
CarmineE120	Carmine (E120) is a colour food additive.
Allura redE129	Allura red (E129) is a colour food additive.
TartrazineE102	Tartrazine (E102) is a colour food additive.
Sunset yellowE110	Sunset yellow (E110) is a colour food additive.
Caramel colorE150	Caramel color (E150) is a colour food additive.

The Southampton study and the warning label

In 2007 a study at the University of Southampton tested six colours alongside sodium benzoate in children, and found a small increase in hyperactive behaviour.¹

The response split by continent. Europe introduced a mandatory warning on any product containing those six: "may have an adverse effect on activity and attention in children". The United States did not, and the FDA's position was that the evidence did not support a causal link for the general population.

Both regulators looked at the same study. Europe's own safety authority agreed the effect was small and the evidence limited. The warning went ahead anyway, which makes it a precautionary decision.

Coverage of the study usually leaves out two details. It tested two mixes of four substances each, six colours in total plus sodium benzoate, and no child received all of them, so nobody knows which one mattered. And the effect size was modest, much smaller than the label's wording suggests.

The warning still had a large practical effect: most European manufacturers reformulated to avoid carrying it. That is why the same brand of sweets comes out brightly synthetic in one country and coloured with fruit concentrate in another.

The six

Tartrazine (E102), quinoline yellow (E104), sunset yellow (E110), carmoisine (E122), ponceau 4R (E124) and allura red (E129).

Tartrazine gets singled out beyond the attention question, with a long-reported association with hives and asthma in a small number of people, mostly those already sensitive to aspirin. The evidence comes from case reports and small trials and is not conclusive.

Carmine, the colour made from insects

Carmine, E120, is made from cochineal insects, and it is the additive most likely to matter to someone for reasons unrelated to health. It fails vegetarian, vegan, kosher and halal diets alike, and it appears in some yoghurts, drinks and sweets where nobody expects an insect-derived ingredient.

It also causes allergic reactions in a small number of people, including anaphylaxis, which is rare for a colour.

Titanium dioxide and the EU ban

E171 was used to make things white and opaque. In 2022 the EU banned it as a food additive after its safety authority concluded that genotoxicity could not be ruled out.² It remains permitted in several other countries, including the United States, so it still appears on imported products.

How to test colours

Colours are among the easiest additives to test, because they are concentrated in a small number of product types: sweets, soft drinks, iced cakes, some breakfast cereals, and children's foods generally.

Cut all synthetic colours for two weeks, which mostly means reading labels on confectionery and drinks, then reintroduce. If you are testing for a child, run it as a proper trial with someone who does not know which week is which, because what you expect to see changes what you notice.

Journal your day in 30 seconds, find your triggers.

Where Triggerbites fits in

This list comes from the food data inside Triggerbites, where every colour is graded by name and E number.

Colours are the additive class people suspect most and test least, usually because nobody remembers which drink or which sweets it was. You journal your day in plain words or by voice, in about 30 seconds: "cereal and orange juice for breakfast, a sandwich and a Fanta for lunch, a bag of sweets in the afternoon, headache by six." The app finds each product in a catalog of over a million and lists the colours in it. Scanning the barcode or photographing the label works too.

Logged this way, two weeks without synthetic colours and two weeks back on them show you whether a pattern is there. The app ranks what your symptoms keep following, including reactions that show up days later, and you can export the record as a PDF for a doctor.

Log your day in 30 seconds

Text, voice or photo. Log as you go, or recap it all in the evening.

Your food, broken down

Meals become ingredients and sensitivity profiles: histamine, salicylates, FODMAPs, allergens, and even the additives on packaged food.

Everything in the same journal

Symptoms, supplements, sleep, stress, exercise and mood, beside what you ate.

See what repeats over time

Patterns between what you eat and how you feel, including delayed reactions that show up days later.

Triggerbites Features

• Log your day in 30 seconds: Text, voice or photo. Log as you go, or recap it all in the evening.
• Your food, broken down: Meals become ingredients and sensitivity profiles: histamine, salicylates, FODMAPs, allergens, and even the additives on packaged food.
• Everything in the same journal: Symptoms, supplements, sleep, stress, exercise and mood, beside what you ate.
• See what repeats over time: Patterns between what you eat and how you feel, including delayed reactions that show up days later.

Common questions

Which food colours carry a warning label?

Six: tartrazine E102, quinoline yellow E104, sunset yellow E110, carmoisine E122, ponceau 4R E124 and allura red E129. Products containing them must say they may have an adverse effect on activity and attention in children.

Do food colours cause hyperactivity?

A 2007 Southampton study found a small increase in hyperactive behaviour from drinks mixing four colours with sodium benzoate. It used two such mixes, six colours in total, and no child received all of them, so nobody knows which substance mattered. Europe added a precautionary warning; the United States concluded the evidence did not support a causal link.

Is carmine vegetarian?

No. Carmine, E120, is made from cochineal insects. It is not vegetarian, vegan, kosher or halal, and it appears in some yoghurts, drinks and sweets where nobody expects an insect-derived ingredient. It also causes rare allergic reactions.

Why was titanium dioxide banned?

The EU banned E171 as a food additive in 2022 after its safety authority concluded that genotoxicity could not be ruled out. It remains permitted in several other countries including the United States, so it still turns up on imported products.

Is tartrazine worse than the others?

It gets singled out for a long-reported association with hives and asthma in a small number of people, mostly those already sensitive to aspirin. The evidence comes from case reports and small trials and is not conclusive.

How do I test whether colours affect me or my child?

Cut all synthetic colours for two weeks, which mostly means reading labels on confectionery and soft drinks, then reintroduce. If testing a child, run it so that whoever judges the behaviour does not know which week is which.

Live, love, log. 🧡